Offshore wind turbines customarily have an external work platform which can be reached via likewise external access ladders and intermediate platforms. The work platform and the access ladders and intermediate platforms are therefore fastened on the circumference of a tower or a transition piece of the offshore wind turbine. The external work platform is generally arranged above the 50 year wave height, i.e., in the north sea or Baltic, for example, approx. 15 m to 20 m above the lowest tidal water level “LTW”, also known under the abbreviation “LAT” for “Lowest Astronomical Tide”. An access opening in the region of the work platform permits access for people to the tower interior.
The external work platform arranged above the 50 year wave height, the access ladders and the intermediate platforms have an influence both on the overall height of the offshore wind turbine and on the dimensioning of the tower structure and foundation structure. The lower passage of the rotor blade tips of the rotor of the offshore wind turbine has to be arranged above the work platform and the structures and attachments located thereon, such as work cranes, walkways or the like. The height of the external work platform therefore indirectly also determines the hub height of the rotor. Furthermore, the access ladders and intermediate platforms cause considerable wave resistance.